Development of Highly Sensitive Iontronic‐Based Tri‐Modal Tactile Sensor for Proximity‐Pressure‐Temperature Sensing

Abstract Flexible tactile sensors with multi‐modal sensing functions have been attracting attention in robotics, while the integrated structural design of multi‐modal tactile sensors and accurate sensing signal decoupling remain technical challenges in applications. This paper presents a novel flexible iontronic‐based tri‐modal tactile sensor that uses the layered ionogel and interdigital electrodes to simultaneously detect proximity, pressure, and temperature. Both the proximity and pressure are detected by capacitance signals, and temperature is measured by resistance changes. This tri‐modal tactile sensor is characterized with remarkable sensing performance, including a proximity detection range of 0–50 mm, linear pressure sensitivity of 5.03 kPa −1 within 0–163 kPa, and temperature detection range of 20–70 °C with sensitivity of −2.196%°C −1 from 20 to 45 °C and −0.822%°C −1 from 45 to 70 °C. The cross‐interference between pressure and temperature is less than 1.15%, meanwhile capacitance signals of proximity and pressure are distinguishable. After that, the 3 × 3 sensor array is mounted to a robotic arm for bottle cup unscrewing experiments, showing that the tactile sensor can accurately detect proximity, pressure, and temperature information in complex operation tasks. This work provides promising paths for multi‐modal iontronic sensing and demonstrates its potential in robotics to facilitate dexterous manipulation.